1. In the â€śCloning Toolâ€ť tab, select the item you want to recolour using the filters at the top, select at least one colour variant to clone, and hit â€śCloneâ€ť. (If youâ€™d recolour a custom thing, youâ€™d use the â€śSelect Custom Packageâ€ť option instead; everything else is the same). Save your package somewhere you can find it again.

2. In the â€śClone Package Editorâ€ť tab, open the package you just cloned. The â€śGeneral Propertiesâ€ť tab shows the general properties (unsurprisingly) of this item, like whether itâ€™s enabled for townies and which ages and genders can wear it. If youâ€™d want to change anything about these properties, youâ€™d do it here.

3. In the â€śRecolour Managerâ€ť tab, itâ€™ll show you the material variants you have cloned; in my case it is only one. Clicking on the small texture preview will open a window from which you can import and export; for this example I exported that texture, removed the stencils and imported it back in. Even when you want to do a completely custom design you will need one of the original textures as a reference; if you paint over the area where that used to be itâ€™ll spill your pattern all over the sim wearing it.

Since all of the in-game textures are already compressed, compression artifacts can become very visible when you make hue/colour changes to an existing texture. But one can tone them down pretty well even in Paint.net: select the affected area (but not the seams or other details), blur it a bit and add noise so it blends in again with the rest.

4. In â€śRecolour Managerâ€ť you can also change the tags, swatches, and other properties of each individual colour variant. In the screenshot I edited the name of my colour variant, removed the swatch (click on the little swatch image, â€śRemoveâ€ť, â€śSaveâ€ť) and changed some of the tags as well as the catalogue swatch colour. One can also change the sort order of the swatches here (â€śSort Orderâ€ť); i just havenâ€™t done that since for the few colours Iâ€™m making, any order is as good as any other.

5. To add more colour variants, use the â€śAdd Recolourâ€ť button at the top. This will copy all settings from the colour variant that you have currently selected, so if you make fifteen shades of blue you donâ€™t need to change the tags for each one. You need to â€śCommit Changesâ€ť when you go from one variant to the next (itâ€™ll also tell you so), or to a different tab. Note that the recolour list is sortable.

6. When youâ€™re done, save your package, and put it in /Mods to test it in game. The screenshot below is from s4pe, showing everything thatâ€™s in the package: since I only added some textures, all there is are my custom textures and CASP resources, no unnecessary duplicates of anything else. CASTools only adds those things to a package that you have explicitely imported or changed â€’ everything else remains referenced to the original item.

7. This is the result in CAS. Since I didnâ€™t change the â€śOrder in Listâ€ť number in General Properties, it will show up right next to the original item (it has the same sort order as that). This is only not obvious in my screenshot since I didnâ€™t scroll up far enough.

You can also customise thumbnails in the â€śThumbnailsâ€ť tab in CASTools. By default the game will generate them by itself automatically though, so you only need to do that if you want to.

If you want to upload CAS recolours on mts, remember that you need to check them out in game too (not just in CAS) and make screenshots of that. See the Creator Guidelines for what exactly is required. Also, when you use other peopleâ€™s material (like textures or illustrations), make sure their ToU allow for that and give credit where credit is due.